Lifting-jack



del) WOODARD.

Lifting ack.

No. 240,801. Patented April 26,1881;

UNITED STATES PATENT OFFICE.

ALVIN N. WOODARD, OF HADLEY, MICHIGAN.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 240,801, dated. April26, 1881.

Application filed November 10, 1880. (No model.)

To all whom it may concern:

Be it known that I, ALVIN NELsoN W001)- ARD, of Hadley, in the county ofLapeer and State of Michigan, have invented certain new and usefulImprovements on Lifting-Jacks and I do hereby declare that the followingis a full, clear, and exact description of the same.

The nature of this invention relates to certain new and usefulimprovements in that class of devices employed in lifting or raisingheavy articles, and which are commonly known as lifting-jacks.

The object of the invention is to construct a device for the purposethat shall combine strength and power, that is easy of operation, andthat can readily be adapted and employed to perform the variousfunctions of a liftingjack, jack-screw, &c.

The invention consists, first, in the peculiar construction andoperation of the cam-lever employed for operating the machine; second,in the peculiar construction and operation of the dogs, in combinationwith the double-faced rack-bar and the cam-lever; third, in theconstruction and arrangement of levers forcontrolling the action of thedogs; and, fourth, in the peculiar construction, arrangement, andcombinations of the various parts, all as more fully hereinafter setforth.

In the drawings, Figure l is a perspective view. Fig.2 is an enlargedinside elevation of one of the cheeks. Fig. 3 is an enlarged perspectiveof. the cam-lever head and its seat. Fig. 4 is a vertical centralsection at right angles to the plane of the cam-lever. Fig; 5 areperspective details of the various pieces composing one of the dogs. 1

p In the accompanying drawings, which form a part of this specification,A represents a rectangular ratchet-bar, the two opposite sides of whichhave a continuous sunken ratchet partially across their face, leaving aplane margin upon both sides. This bar terminates in a ball, a, at thetop, and at the lower end in a T-shaped foot, I). I

B B and B B are two sets of dogs. The lower set, B, which act uponopposite sides of the bar A, slide in corresponding sockets in the innerfaces of the checks 0 O, which form the body of the machine, ashereinafter described. The lower dogs, B, have a lateral movement orplay in their respective sockets, and firmly resist any tendency toother displacement. v

c are coil-sprin gs attached at one end to the spring-plate d, and restin proper sockets back of the dogs, and exert their force against thedogs in such a manner as to press them firmly against the rack-bar,while their elasticity allows the bar to slide upward, but holds thesame securely against any downward strain. These dogs are provided upontheir rear faces with a loop, 0, through which passes a bolt, f, thecut-away portion 9 of which performs the function of a cam, when thebolt is turned, to withdraw the dog from its engagement with theratchetbar. These bolts fpass out through the cheeks, and are connectedat their outer ends, upon one side, by a bell-crank lever, D, by meansof which the operatorcan simultaneously throw the dogs in or out ofengagement with the ratchet-bar.

The upper dogs, B, are of the same construction as the lower dogs, buthave, in addition to them, a vertical reciprocating movement, which isimparted to them by the following devices.

It represents a rectangular frame with an opening large enough toreceive the dog and allow of lateral play therein, while the frame issusceptible of a vertical movement between the cheeks.

'5 represents links provided upon each end with circular heads, whichare centrally perforated. Oneend of each of theselinksis placed over apin, j, in the lower portion of each frame h, the body of which is cutaway around such pins to receive the circular heads of the links, whichfit snugly therein.

A bolt, is, passes through the cheeks and through the loops in the rearof the dogs in such a manner as to perform the same functions as thebolts f of the lower dogs, but so situated as-not to interfere with thevertical play of the dogs. These bolts k are also connected together andoperated by a bell-crank lever, E.

F represents the actuating-lever, the arms of which are screwed into orotherwise removably secured to the cylindrical lever-head I, from thetwo sides of which project a central round lug or pin, m, by means ofwhich the.

too

head is properly pivoted or journaled in suitable bearings formed in theinner faces of the checks, which are sufficiently cut away to allow of afree oscillating movement being given to the lever. Through the head 1is formed an opening, a, sufficiently large to allow the ratchet-bar A afree movement through the same in any position the head may assume. Thelinks i, one end of each of which is pivotally secured to the lowerportions of the frames h, have their lower ends in like manner pivotallysecured to the head, as is clearly shown in Figs. 2 and 4 of thedrawings.

The checks 0 G are both alike, and are rigidly secured together byproper bolts, and are recessed to receive the working parts abovedescribed. To avoid the danger of the ratchetbar binding upon the innerfaces of the cheeks, friction-rollers 0 are properly journaled at topand bottom, between which the ratchet-bar moves, said rollers 0 bearingupon the plane margin of the gar, upon either side of the ratchet-teeth.For the same purpose frictionrollers 19 are placed upon the bolts whichsecure the two cheeks together, such rollers hearing upon the edge oftheratchet-bar, the cheeks being sufficiently cut away to receive them andallow of their free action.

It will be seen that, all the parts being in engagement and free toperform their various functions, one arm of the lever F being depressedwill cause the links 2' to assume a position at an angle to thevertical, and that in assuming this position the upper dogs are drawndown into theirlowestposition. By raising the lever to the horizontalthe dogs are forced upward by the links, and by reason of the engagementof the dogs with the ratchetbar the latter must necessarily be raised inthe same degree. At this time the lower dogs have engaged with theratchet-bar and retain it in its elevated position. A continued upwardmovement of the same lever will cause the links to draw down the upperdogs and make a fresh engagement with the ratchet-bar, this oscillatingmovement of the lever being continued until the ratchet-bar has beenraised the entire length of its ratchet, or the article to which it issecured is elevated to the height desired.

It will be seen, in the operation above described, that the pins j,which pivotally secure the links t to the lever and dog-frames, arecalled upon to perform but one functionthat is, to draw the dogs andframes down as thelever is elevated or depressed above or below thehorizontal, while the strain in lifting depends upon the links and theirresistance to compression. To give slack to the ratchet-bar, the

of chains passing through the rings H, which project above the top ofthe device and form a part of bolts 1, rigidly secured to the sides ofthe cheeks, and project below the same and afford meauslfor securing thedevice to a proper pedestal, if desired.

What I claim as my invention is 1. In a lifting-jack, two sets ofratchetfaced dogs, one set actuated by an oscillating lever and adaptedto raise the ratchet-bar, and the other set acting as a pawl upon theratchetbar to retain it in its elevated position, substantially asdescribed.

2. In aliftingjack, a set of ratchet-faced dogs, B, susceptible oflateral play in the body of the device, in combination with cam-bolts f,springs c, and bell-crank lever I), by means of which both dogs may besimultaneously operated, substantially as set forth.

3. In a liftingjack, a set of ratchet-faced dogs, B, susceptible of alateral and a vertical reciprocating movement in the body of the device,in combination with the bolts 70, by means of which the dogs may beretracted at any point of their vertical movement, substantially asspecified.

4. In a liftingjack, a set of ratchet-faced dogs, B, susceptible of alateral and a vertical reciprocating movement, substantially asdescribed, in combination with the frames h, links 1', and lever F,substantially as and for the purpose set forth.

5. In a lifting-jack, the ratchet-bar A, provided with a continuoussunken ratchet upon two opposite faces, with a plane margin at eachedge, in combination with friction-rollers which bear upon the fourfaces of the rack-bar, substantially as set forth.

6, In a lifting -jack, the lever F, pivotally secured in the frame, andhaving two links, *6, stepped in its upper portion and abutting againstthe frames which carry the dogs, exertin g a pushing force upon saiddogs, whereby the ratchet-bar is raised, substantially as and for thepurpose specified.

Detroit, Michigan, September 14, 1880.

ALVIN N. WOODARD.

In presence of- H. S. SPRAGUE, J. PAUL MAYER,

